Liu F.-X.,State Key Laboratory of Advanced Stainless Steel Materials |
Liu F.-X.,Shanxi Taigang Stainless Steel Co.
Kang T'ieh/Iron and Steel (Peking) | Year: 2010
The aging treatment for S32205 duplex stainless steel was preformed at 850°C. σ phase precipitation and its effect on mechanical properties of S32205 duplex stainless steel were analyzed by OM, SEM, EDS, hardness measurements and tensile tests. The results show that σ phase begins to nucleate at γ/α or α/α interfaces after 15 min aging, and then grows into the surrounding ferrite areas. The formation mechanism is a transformation of α into γ2 and σ. The amount of σ phase increases with prolonging aging time, which achieves 18% when aging for 240 min, and the formed σ phase in S32205 duplex stainless steel leads to an obvious increase in the hardness, a certain increase in the strength and a sharp decrease in the ductility. The types of tensile fracture are changing from the typical ductile rupture to the brittle fracture characterized by quasi-cleavage crack.
Li G.-P.,Taiyuan University of Technology |
Li G.-P.,Shanxi Taigang Stainless Steel Co. |
Li G.-P.,State Key Laboratory of Advanced Stainless Steel Materials |
Li J.-C.,Shanxi Taigang Stainless Steel Co. |
And 7 more authors.
Kang T'ieh/Iron and Steel | Year: 2013
The influence of different hot treatments on mechanical properties, metallurgical structure and corrosion resistance of S32003 DSS was investigated. The results show that with the increasing of temperature range from 850°C to 1100°C, the strength and hardness of S32003 plate were decreased, and elongation increased. During heat treating at 850-900°C, saw-tooth and spotted second phases can be precipitated in the ferrite grain and on the phase boundaries between ferrite and austenite which will be harmful to corrosion resistance. The second phases was solved as heat treating above 950°C. The phase structure analysis by TEM shows that these second phases are Cr2N.
Zou D.-N.,Xian University of Architecture and Technology |
Han Y.,Xian University of Architecture and Technology |
Zhang W.,Xian University of Architecture and Technology |
Zhang W.,State Key Laboratory of Advanced Stainless Steel Materials |
Fang X.-D.,State Key Laboratory of Advanced Stainless Steel Materials
Journal of Iron and Steel Research International | Year: 2010
To investigate the influence of tempering process on microstructural evolutions and mechanical properties of 00Cr13Ni4Mo supermartensitic stainless steel (SMSS), specimens were tempered in the temperature range of 520-720 °C for 3 h followed by air cooling and an optimized tempering temperature was chosen to prolong holding time from 3 to 12 h. After heat treatments, microstructure examination was conducted by scanning electron microscope, X-ray diffraction examinations, hardness measurements and tensile tests. The results revealed that the superior mechanical properties were achieved by quenching at 1040 °C for 1 h+water cooling and tempering at 600 °C for 3 h + air cooling. Increasing isothermal tempering time could improve the toughness notably. It was believed that the property was correlated with the microstructure of tempered lath martensite and retained austenite. More retained austenite content is beneficial to the higher toughness of the SMSS. © 2010 Central Iron and Steel Research Institute.